Traverse mechanism



July 26, 1955 s. B. ROBERTS ET AL TRAVERSE MECHANISM 2 Sheets-Sheet 1Filed NOV. 9, 1951 INVENTORS. SAMUEL B. R

ERTS MAN OB EL ROBERT H. ROUGHSEDGE GEORGE E. KOSLOW W ABRAHAM EDTRAVERSE MECHANISM Filed NOV. 9, 1951 2 Sheets-Sheet 2 a 2mm 67INVENTORS. 77 I SAMUEL B. ROBERTS ABRAHAM EDELMAN ROBERT H. ROUGHSEDGE7g GEORGE E. KOSLOW WQT OI-QN EYS.

nited States Patent Ofilice 2,713,980 Patented July 26, 1955 TRAVERSEMECHANISM Samuel B. Roberts, Greenwich, Conn, Robert H. Roughsedge,Ramsey, N. 3., and Abraham Edelrnan and George E. Koslow, New York, N.Y., assignors to Celanese Corporation of America, New York, N. Y., acorporation of Delaware Application November 9, 1951, Serial No. 255,642

9 Claims. (Cl. 242158) This invention relates to a traverse mechanismand relates more particularly to a traverse mechanism for use in thewinding of yarn at high speeds.

In the packing of yarn and the like, such as yarn, filaments, threads,wire, etc., all of which will hereinafter be referred to as yarn, it isa common practice to wind said yarn into a so-called cross-wound packingin which the turns of yarn lie on the package at a relatively largeangle. Usually, these packages are headless, that is they are notprovided with end flanges to support the yarn, but. depend upon therigidity of the winding itself to maintain the shape of the package. Themost widely employed yarn packages of this type are cones and cheeses.

The winding machines that are employed for the production of cross-woundpackages are equipped with a traverse mechanism operatively connected toa yarn guide, which traverse mechanism reciprocatcs back and forth alongthe length of the package to guide the yarn onto the package at thedesired angle. These traverse mechanisms are generally operated by meansof cams or other mechanical means. If an attempt is made to carry outthe winding operation at high speeds, it is found that these mechanicaltraverse mechanisms are inadequate owing either to excessive Wear orexcessive stresses that are imposed upon the parts thereof when thetraverse speed exceeds a certain value. As a result, it is not possibleto operate these traverse mechanisms above certain speeds, which therebylimits the maximum winding speeds that can be employed in the productionof cross-wound packages.

Among the difficulties that are frequently encountered with theconventional mechanical traverse mechanisms is the tendency of the yarnwindings to cross-thread and to ribbon. Cross-threading occurs when,owing to the relatively slow reversal of the traverse mechanism at theend of its stroke, an important fraction of a turn of yarn is wound ontothe end of the package Where it can fall out. A yarn package in whichsuch falling out has occurred is difficult to unwind smoothly, if suchunwinding can be successfully accomplished at all. Ribboning is theresult of the tendency of the traverse mechanism to operate at such aratio to the speed of rotation of the yarn package, at one or more timesduring the winding of the said package, as to lay a number of yarnsalmost on top of one another. This produces a yarn package having anuneven surface and causes yarn slippage and loose packages. Ribboningalso permits interlocking of the turns of yarn which prevents easyunwinding of the yarn package.

It is an important object of this invention to provide a traversemechanism which will be free from the foregoing and other disadvantagesand which will be especially simple in construction and efiicient inoperation.

A further object of this invention is to provide a traverse mechanism inwhich electrical means are employed to provide the desired reciprocatorymotion of the yarn guide.

Another object of this invention is to provide a traverse mechanism inwhich elastic or resilient means are provided at each end of thetraverse stroke to cause a rapid reversal of the direction of motion ofthe yarn guide.

Other objects of this invention, together with certain details ofconstruction and combinations of parts, will be apparent from thefollowing detailed description and claims.

According to the present invention, there is provided, in a traversemechanism having a reciprocating element operatively connected to a yarnguide, an elastic member positioned at each end of the traverse stroke.The reciprocating element strikes the elastic member at each end of itsstroke, compressing the same and thereby converting its kinetic energyof motion into potential energy of the compressed elastic member. Theelastic member stops the reciprocating element and then expands,returning its potential energy to the reciprocating element in the formof kinetic energy of motion and causing said reciproeating element tomove toward the opposite end of its traverse stroke. By means of thisconstruction, there is obtained a rapid reversal of the reciprocatingelement at each end of its stroke without the imposition on anymechanisms of excessive stresses. The reciprocating element need notstrike the elastic member directly, but may act thereon indirectlythrough any suitable means such as a linkage or the like. Also, theelastic member may be carried by the reciprocating element.

To operate successfully, the elastic members must be designed so as tobe capable of sufficient compression to convert substantially all thekinetic energy of the reciprocating element into the form of potentialenergy. If the elastic members are not capable of this, as, for example,if stops are provided which will limit the compression of the elasticmembers the kinetic energy of the reciprocating element will not be allsubstantially converted to potential energy and will not be returned tothe reciprocating element through the expansion of the elastic members.The stresses developed in the elastic members should, of course, be lessthan the elastic limit of the material of which they are constructed toavoid producing a permanent set in said members. The elastic membersshould be supported solidly in such a manner that there is no tendencyfor any movement of their supported portions relative to their supportsto take place which would prevent the kinetic energy of thereciprocating element from being converted to potential energy of theelastic members. Advantageously, the elastic members should be designedso as to supply at least about one-third and preferably at least abouttwo thirds of the energy required to start the movement of thereciprocating element from one end to the other end of its traversestroke.

During the movement of the reciprocating element through its traversestroke, certain unavoidable losses take place as the result of friction,windage and the like which will tend to slow down and finally stop thereciprocating element. To compensate for these losses, means areprovided which will furnish energy to the reciprocating element in timedrelation to its movement through the traverse stroke. These means may beelectrical in nature and may take the form of electromagnets operatingon a portion of the reciprocating element which is constructed of amagnetic material. For eX- ample, the reciprocating element may comprisea permanently magnetized cylinder which is supported slidably betweentwo solenoid coils that may be energized so that each solenoid coilalternately attracts and repels the pole of the magnet adjacent thereto.The elastic members may comprise helical springs extending into the coreof the solenoid coils so that the magnet will strike the same at eachend of its traverse stroke. The solenoid coils may be energized withalternating current having a frequency equal to the desired traverserate or with direct current whose direction is reversed at the desiredrate, as, for example, by means of a commutator. The solenoid coil whichattracts the magnet will tend to increase its degree of magnetization.However, the solenoid coil which repels the magnet will tend todemagnetize the same. To prevent any change in the strength of themagnet, it may be desirable to design the apparatus so that a smallercurrent will flow through the solenoid coil which is repelling themagnet. Instead of having two solenoid coils, a single solenoid coil maybe employed alternately to repel and attract the magnet.

The traverse mechanism may also be operated with a soft iron bar inplace of the permanent magnet. In this case, the solenoid coils areenergized alternately to attract the end of the iron bar adjacentthereto. To obtain the most eflicient use of electrical energ thesolenoid coils should be energized so that they both tend to magnetizethe iron bar in the same direction. In general, the reciprocatingelement is not positively connected to the means furnishing energythereto to overcome losses.

The reciprocating element tends to move through its traverse stroke at asubstantially constant velocity due to inertia. If the losses that takeplace during its movement are compensated for by the energy addedthereto, the velocity will remain substantially constant throughout itsstroke producing a uniformly wound package. For some purposes, it may bedesirable to vary the velocity of the reciprocating element or to varythe amount of energy supplied thereto during its traverse stroke whichmay be accomplished readily, for example, by changing the amount ofcurrent supplied to the solenoid coils. This change in current may beeffected by the use of a suitably designed alternating current generatoror by means of a suitable commutator arrangement.

Because there is no fixed relationship between the frequency of thetraverse motion and the speed of rotation of the yarn package, thetendency for ribboning to occur is reduced to a minimum. Substantiallyto prevent all ribboning, there may be provided means for varying thefrequency of the traverse motion at frequent intervals during thewinding operation in accordance with some predetermined program. Thisvariation may, for example, be accomplished by changing the frequency ofthe current through the solenoid coils in accordance with the desiredchanges in the frequency of the traverse motion. When the changes in thefrequency of the traverse motion are relatively large, means may beprovided for simultaneously changing the current through the solenoidcoils so that it will be at the optimum value for each frequency. Thechange in the frequency of the traverse motion not only eliminatessubstantially all tendency toward ribboning, but also prevents thedevelopment of resonant motions in the elastic members which might leadto fatigue failures in said members.

A single power supply may be used to provide current for a large numberof traverse mechanisms which may be located at some distance from thepower supply. This arrangement is particularly advantageous when thetraverse mechanisms are to be operated in a hazardous atmosphere sinceit enables a great deal of the electric equipment to be removed fromsaid atmosphere. The equipment, or part of it, may be constructed foroperation in a hazardous atmosphere by sealing the same from contactwith said atmosphere.

The winding apparatus with which the traverse mechanism of thisinvention is employed may be of any suitable construction of which thereare many types known in the art. It may drive the yarn package throughfrictional contact with the surface thereof or it may drive the spindleon which said yarn package is supported The windlng apparatus mayoperate at a constant rotational speed or it may drive the yarn packageat a constant peripheral speed.

The traverse mechanism of this invention will now be describedspecifically as applied to the winding of a plurality of yarn windingson a single yarn package support. It may, however, also be employed forthe winding of a single yarn winding on a yarn package support.

A preferred embodiment of this invention is shown in the accompayingdrawings wherein:

Fig. l is a plan view of the traverse mechanism,

Fig. 2 is a cross-sectional view, taken along the line 2-2 in Fig. l, inthe direction of the arrows,

Fig. 3 is a detail cross-sectional view, taken along the line 3-3 inFig. l, in the direction of the arrows,

Fig. 4 is a detail cross-sectional view, taken along the lines 4-4 inFig. l, in the direction of the arrows,

Fig. 5 is a schematic circuit diagram of the electric wiring of thetraverse mechanism,

Fig. 6 is a view showing a cross-wound yarn package free from ribboning,and

Fig. 7 is a view showing a cross-wound yarn package in which ribboninghas taken place.

Referring now to the drawings, the reference numeral 11 designates abase plate to which is securely fastened an upright 12. Mounted on theupright 12 are a pair of pillow blocks 13 in which is journalled forrotation a shaft 14 carrying a cork roll 15. The shaft 14 supports anadjustable sheave 16 driven by the V-belt 17 from motor-pulley 18 andmotor 19. A knurled head screw 21 threaded into supporting bracket 22mounted on the upright 12 enables the effective diameter of the pulley16 to be adjusted over a considerable range whereby the speed ofrotation of the shaft 14 and the cork roll 15 may be varied.

Another upright 23 fastened to the base plate 11 has mounted thereon apillow block 24 in which is journalled for rotation a shaft 25. Mountedon the shaft 25 is bifurcated arm 26 carrying spindle shaft 27 whichsupports spindle chuck 28 adapted to engage and hold yarn packagesupporting tube 29 on which a pair of yarn windings 31 and 32 are to beformed. The yarn package supporting tube 29 is driven at a constantperipheral speed by frictional contact between the said tube, or theyarn windings 31 and 32 thereon, and the cork roll 15. To regulate thepressure with which the yarn package supporting tube 29, or the yarnwindings 31 and 32, bear against the cork roll 15, there is mounted onthe shaft 25 an arm 33 to which a counterweight 34 is adjustably securedby means of a set screw 35. Also fastened to the shaft 25 is an arm 36which is secured by means of a pin 37 and a clevis 38 to plunger 39 of ahydraulic dashpot 41 which serves to keep the spindle shaft 27 and theelements supported thereon from bouncing away from contact with the corkroll 15.

Yarns 42 and 43, from any suitable source (not shown), are guided toform the yarn windings 31 and 32, respectively, by means of a traversemechanism, indicated generally by reference numeral 44. The traversemechanism 44 comprises a cylindrical permanent magnet 45 which isslidably mounted between a pair of spaced solenoid coils 46 and 47 thatare each provided with a liner of nonmagnetic material 48 that serves asa bearing for the magnet 45. Positioned adjacent the outer ends of thesolenoids 46 and 47, respectively, are heavy metal blocks 49 and 51 thatare fastened securely to the upright 12. The blocks 49 and 51 carrysprings 52 and 53 that project into the hollow cores of the solenoids 46and 47, respectively. As shown in Figure 4, the springs 52 and 53 arethreaded onto the heads of screws 54 that extend into the supportingblocks and the said springs are held in place by means of set screws 55.

Fastened to the magnet 45 is a strap 56 to one end of which is secured acounterweight 57 and to the other end of which is secured a cross-arm 58that carries a pair of self-threading yarn guides 59 and 61 that guidethe'ya'rns 42 and 43 to form the yarn packages 31 and 32. To preventrotation of the strap 56 and to maintain the yarn guides 59 and 61properly positioned, there is provided a bracket 62 which extendsoutwardly from the upright 12. Fastened to the bracket 62 is ahalf-round bar 63 which is recessed to form a Slot 64 through which thestrap 56 extends and which prevents rotation thereof. The counterweight57 prevents the development of unbalanced inertia forces in the traversemechanism during the reverse of movement of the magnet 45.

The solenoids 46 and 47 are energized by means of the electrical circuitshown in Figure 5 of the drawings to traverse the magnet and the yarnguides 59 and 61 operatively connected thereto back and forth. Referringnow to this figure, there are provided a pair of direct current powerterminals 65 and 66 from which a current flows to switching motor 67comprising a field coil 68 and an armature 69. Mounted on the shaft ofthe switching motor 67 is a commutator 71 and slip rings 72 and 73 whichare connected to the solenoid coils 46 and 47. Current fiows from thepower terminals 65 and 66 to the solenoid coils 46 and 47 by way of thecommutator 71 and the slip rings 72 and 73 through a voltage dividernetwork, indicated generally by reference numeral 74 and comprising avariable resistor 75, whose function will be described more fullyhereinafter, a variable resistor 76, which permits the current throughsaid coils to be regulated, and a pair of fixed resistors 77 and 78.Sparking of the commutator 71 and the slip rings 72 and 73 iseffectively prevented by means of a pair of capacitors 79 connectedacross the solenoid coils 64 and 47.

The direction of the flow of the current through the solenoid coils 46and 47, and the polarity of the magnetic field generated by saidsolenoid coils, is reversed periodically by the rotation of thecommutator 71 and the slip rings 72 and 73. This reversal in thepolarity of the magnetic field causes each of the solenoid coils 46 and47 alternately to attract and repel the end of magnet 45 adjacentthereto, thereby moving the said magnet, and the yarn guides 59 and 61operatively connected thereto, back and forth. At the end of its stroke,the magnet 45 will strike one of the springs 52 or 53 and will compressthe said spring converting the kinetic energy of said magnet intopotential energy in said spring. Then, the spring expands, returning thepotential energy, nearly without loss, to the magnet 45 and causing thesaid magnet to move in the opposite direction. At the other end of itsstroke, the magnet 45 will strike the other of the springs 52 or 53 andthe process will be repeated. Because of the storage and return to thesystem of the energy in the magnet 45 by the springs 52 and 53, thesolenoid coils 46 and 47 only have to furnish sufficient energy to themagnet 45 to overcome the frictional, windage and like losses in themoving system comprising the magnet 45 and the elements connectedthereto rather than the entire energy needed to effect the traversemotion.

The solenoid coil which is attracting the magnet 45 will tend tostrengthen the magnetization of said magnet. However, the solenoid coilwhich is repelling the magnet 45 will tend to demagnetize the saidmagnet. To prevent any such demagnetization from taking place, there isprovided a resistor 80 which shunts the solenoid coil 46 or 47 which isrepelling the magnet 45, thereby reducing the current through the saidsolenoid coil and limiting the magnetic field thereof to a safe value.

To change the frequency of the traverse motion, the speed of theswitching motor 67 is altered by adjusting the rheostat 81 which isconnected in series with the armature 69 of said motor. In starting upthe traverse mechanism, it may be desirable to build up the frequency ofthe traverse motion gradually by bringing the switching motor up tospeed slowly. This may be achieved simply, for example, by connectingcarbon filament lamps 82 in series with the armature 69. The carbonfilament lamps exhibit a negative temperature-coefiicient of resistanceso that 6 the current through them increases gradually as they heat upcausing the speed of the motor 67 to increase gradu ally during thestart-up period.

Ribboning is effectively prevented by changing the frequency of thetraverse motion periodically. To achieve this change, there is provideda timer 83 which alternately opens and closes a contact 84 connectedacross a rheostat 85 in series with the armature 69. When the contact 3closes, the rheostat is shorted out of the armature circuit and thespeed of the switching motor 67 increases causing the frequency of thetraverse motion to increase. On the other hand, when the contact 84opens, the speed of the switching motor 67 and the frequency of thetraverse motion decrease. The change in the frequency of the traversemotion caused by the opening and closing of the contact 84 may beregulated by adjusting the rheostat 85.

When the change in the frequency of the traverse motion caused by theopening and closing of the contact 84 is relatively large, it isdesirable to adjust the current fiowing through the solenoid coils 4 6and 47 to the optimum value for each frequency. This adjustment may beeffected readily by means of a contact 86 in the timer 83 which opensand closes synchronously with the contact 84 and is connected across therheostat 75. When the contact 86 closes, it shorts out the rheostat 75so that the current through the solenoid coils 46 and 47 will increase.On the other hand, when the contact 86 opens the current through thesolenoid coils 46 and 47 will decrease.

During operation, the motor 19 drives the cork roll 15 at a constantperipheral speed causing the yarn packages 31 and 32 to rotate at aconstant peripheral speed to wind the yarns 42 and 43 thereon. The yarns42 and 43 are cross-wound onto the yarn packages 31 and 32 by thetraverse mechanism 44 without cross-threading. In addition, because ofthe periodic changes in the frequency of the traverse motion, the finalyarn package will be free from ribboning as shown at 37 in Fig. 6 of thedrawings. Yarn packages produced with conventional traverse mechanisms,on the other hand, exhibit ribboning as shown in the package 88 in Fig.7 of the drawings in which a plurality of yarns are wound closelyadjacent to one another as at 89 to produce a rough, irregular spot insaid yarn package.

It is to be understood that the foregoing detailed description is givenmerely by way of illustration and that many variations may be madetherein without departing from the spirit of our invention.

Having described our invention, what we desire to secure by LettersPatent is:

1. In a traverse mechanism, the combination with a reciprocating elementcomprising a magnet operatively connected to a yarn guide, ofelectromagnetic means acting alternately to attract and repel each poleof said magnet for moving said reciprocating element through itstraverse stroke, said electromagnet means including resistance means toproduce a smaller force when tending to repel said magnet than whentending to attract said magnet whereby the tendency to demagnetize saidmagnet is kept at a minimum.

2. In a traverse mechanism, the combination with a reciprocating elementoperatively connected to a yarn guide, of electrical means for movingsaid reciprocating element through its traverse stroke by means of aseries of electrical pulses, and means for periodically andautomatically changing the frequency of the electrical pulses to changethe frequency of the traverse motion.

3. In a traverse mechanism, the combination with a reciprocating elementoperatively connected to a yarn guide, of elastic members positioned inthe path of the reciprocating element and arranged to be struck therebyat the end of the traverse stroke of said reciprocating element to stopand reverse the direction of movement of the said reciprocating element,and means for periodically and automatically changing the frequency ofthe traverse motion.

4. In a traverse mechanism, the combination with a reciprocating elementoperatively connected to a yarn guide, of elastic members positioned inthe path of the reciprocating element and arranged to be struck therebyat the end of the traverse stroke of said reciprocating element to stopand reverse the direction of movement of the said reciprocating element,means for supplying sufficient energy to the reciprocating element intimed relation to its motion to overcome the energy losses tending toslow down said reciprocating element, and means for periodically andautomatically adjusting said energy supplying means for changing thefrequency of the traverse motion.

5. In a traverse mechanism, the combination with a reciprocating elementcomprising a magnet operatively connected to a yarn guide, of elasticmembers positioned in the path of the reciprocating element and arrangedto be struck thereby at the end of the traverse stroke of saidreciprocating element to stop and reverse the direction of movement ofthe said reciprocating element, and solenoids acting alternately toattract and repel the magnet for supplying sufiicient energy to thereciprocating element in timed relation to its motion to overcome theenergy losses tending to slow down said reciprocating element, and meansfor periodically and automatically adjusting the frequency of thecurrent to said solenoids for changing the frequency of the traversemotion.

6. In a traverse mechanism, the combination with a reciprocating elementcomprising a magnet operatively connected to a yarn guide, of elasticmembers positioned in the path of the reciprocating element and arrangedto be struck thereby at the end of the traverse stroke of saidreciprocating element to stop and reverse the direction of movement ofthe said reciprocating element, and solenoids acting alternately toattract and repel the magnet for supplying sufficient energy to thereciprocating element in timed relation to its motion to overcome theenergy losses tending to slow down said reciprocating element, and meansfor periodically and automatically adjusting the frequency of thecurrent to said solenoids for changing the frequency of the traversemotion, said solenoid means including resistance means to produce asmaller force when tending to repel said magnet than when tending toattract said magnet whereby the tendency to demagnetize said magnet iskept at a minimum.

7. In a traverse mechanism, the combination with a cylindrical magnet,of a pair of solenoid coils slidably supporting said magnet actingalternately to attract and repel each pole of said magnet for movingsaid reciprocating element through its traverse stroke, a pair ofsprings positioned at the ends of the traverse stroke in the path of themagnet and arranged to be struck thereby to stop and reverse thedirection of movement of the magnet, and means for periodically andautomatically adjusting the frequency of the current to said solenoidsfor changing the frequency of the traverse motion.

8. In a traverse mechanism, the combination with a cylindrical magnet,of a pair of solenoid coils slidably supporting said magnet actingalternately to attract and repel each pole of said magnet for movingsaid reciprocating element through its traverse stroke, a pair ofsprings positioned at the ends of the traverse stroke in the path of themagnet and arranged to be struck thereby to stop and reverse thedirection of movement of the magnet, and means for periodically andautomatically adjusting the freqeuncy of the current to said solenoidsfor changing the frequency of the traverse motion, said solenoid meansincluding resistance means to produce a smaller force when tending torepel said magnet than when tending to attract said magnet whereby thetendency to demagnetize' said magnet is kept at a minimum.

9. In a traverse mechanism, the combination with a cylindrical magnet,of a pair of solenoid coils slidably supporting said magnet actingalternately to attract and repel each pole of said magnet for movingsaid reciprocating element through its traverse stroke, a pair ofsprings positioned at the ends of the traverse stroke in the path of themagnet and arranged to be struck thereby to stop and reverse thedirection of movement of the magnet, and means for periodically andautomatically adjusting the frequency of the current to said solenoidsfor changing the frequency of the traverse motion, and means forsimultaneously and automatically varying the current to the solenoids tothe optimum value for each frequency, said solenoid means includingresistance means to produce a smaller force when tending to repel ,saidmagnet than when tending to attract said magnet whereby the tendency todemagnetize said magnet is kept at a minimum.

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